1.1 Experimental Design (5086/5105)

Pipette can measure 25.61cm³

• True

• False

Answer explanation

Pipette measures 25.0cm3 (fixed volume)

25 cm³ of an alkali are added to 20 cm³ of an acid.

The temperature change is measured.

Which apparatus is not needed in the experiment?

• 25 cm³ measuring cylinder

• 100 cm³ beaker

• electronic balance

• thermometer

A student put 25.0 cm³ of dilute hydrochloric acid into a conical flask.

The student added 2.5 g of solid sodium carbonate and measured the change in temperature of the mixture.

Which apparatus does the student need to use to obtain the most accurate results?

• electronic balance, measuring cylinder, thermometer

• electronic balance, pipette, stopwatch

• electronic balance, pipette, thermometer

• burette, pipette, thermometer

Answer explanation

2.5g --> Mass! --> Electronic balance

25.0cm3 of liquid --> Pipette

Temperature --> Thermometer

Which apparatus is used to measure 20.10cm³ of hydrochloric acid?

• burette

• pipette

• measuring cylinder

• gas syringe

Answer explanation

20.10cm3 liquid is measured by burette.

2dp --> accurate volume

Which apparatus is used to measure 20.10 cm³ of hydrogen gas?

• burette

• pipette

• measuring cylinder

• gas syringe

A student mixes 25cm³ samples of dilute hydrochloric acid with different volumes of aqueous sodium hydroxide. In each case, the student measures the change in temperature to test if the reaction is exothermic.

Which piece of apparatus is not needed?

• A

• B

• C

• D

Solid R reacted with dilute sulfuric acid. The initial temperature of the dilute sulfuric acid and the final temperature of the solution are shown.

What was the change in temperature in °C?

• – 6

• – 4

• 6

• 4

Which piece of apparatus is used to measure exactly 26.30cm³ of a liquid?

• A

• B

• C

• D

A student wishes to add exactly 13.20 cm³ of alkali to exactly 25.0 cm³ of an acid as part of an experiment.

Which apparatus should the student use to measure these volumes?

• alkali: pipette; acid: burette

• alkali: measuring cylinder; acid: gas syringe

• alkali: burette; acid: pipette

Which apparatus is used to measure 20cm³ of water?

• burette

• pipette

• measuring cylinder

• gas syringe